CA-125 Immune Complexes as Biomarkers of Ovarian Cancer

Abstract

The invention is directed to assays of CA-125 immune complexes that can be used diagnostically. It also includes glass or plastic plates or slides on which the monoclonal antibodies against CA-125 have been immobilized and kits containing these plates or slides.

1 . A method of assaying the amount of CA-125 immune complex in a test biological sample derived from a woman, comprising contacting said test biological sample with an antibody that binds to human anti-CA125 antibody. 
     
     
         2 . The method of  claim 1 , wherein said biological sample is blood, plasma, or serum. 
     
     
         3 . The method of  claim 2 , wherein said human antibody is a human IgG. 
     
     
         4 . The method of  claim 1 , wherein said woman has clinical factors indicating that she is at increased risk of having or developing ovarian cancer or has been previously diagnosed as having ovarian cancer and said method is being used to test for disease recurrence. 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , wherein said woman has, within the previous three months, had a diagnostic assay performed measuring free CA-125 levels in a sample of blood serum or plasma from said woman. 
     
     
         7 . The method of  claim 1 , wherein said method comprises:
 a) obtaining said test biological sample from said woman;   b) incubating said test biological sample with a monoclonal antibody to CA-125, wherein said monoclonal antibody has been immobilized on a solid support and said incubation is carried out under conditions permitting the binding of said monoclonal antibody to said CA-125 when said CA-125 is in an immune complex;   c) at the end of the incubation of step b), separating said solid support with immobilized monoclonal antibody and bound immune complexes from said test biological sample;   d) incubating said solid support with immobilized monoclonal antibody and bound immune complexes obtained in step c) with a detectably labeled antibody that binds to human antibody;   e) at the end of the incubation of step d), separating the solid support with bound detectably labeled antibody from unbound detectably labeled antibody;   f) quantitating the amount of detectable label bound to said solid support.   
     
     
         8 . The method of  claim 7 , wherein said test biological sample is blood, plasma, or serum. 
     
     
         9 - 12 . (canceled) 
     
     
         13 . The method of  claim 8 , wherein said woman has clinical factors indicating that she is at increased risk of having or developing ovarian cancer or has been previously diagnosed as having ovarian cancer and said method is being used to test for disease recurrence. 
     
     
         14 . (canceled) 
     
     
         15 . The method of  claim 8 , wherein said woman has, within the previous three months, had a diagnostic assay performed measuring free CA-125 levels in a sample of blood serum or plasma from said woman. 
     
     
         16 . A method of diagnostically testing a woman for ovarian cancer, comprising determining the amount of CA-125 immune complexes present in a biological sample obtained from said woman. 
     
     
         17 . The method of  claim 16 , further comprising determining the amount of free CA-125 present in a biological sample obtained from said woman. 
     
     
         18 . The method of  claim 16 , wherein said biological sample is blood, plasma, or serum. 
     
     
         19 . The method of  claim 18 , wherein said human antibody is a human IgG. 
     
     
         20 . The method of  claim 18 , wherein said woman has clinical factors indicating that she is at increased risk of having or developing ovarian cancer. 
     
     
         21 . The method of  claim 18 , wherein said woman has been previously diagnosed as having ovarian cancer and said method is being used to test for disease recurrence. 
     
     
         22 . The method of  claim 18 , wherein said woman has, within the previous three months, had a diagnostic assay performed measuring free CA-125 levels in a sample of blood serum or plasma from said woman. 
     
     
         23 . (canceled) 
     
     
         24 . The method of  claim 17 , wherein the amount of free CA-125 in said biological sample is determined by a method comprising:
 a) incubating said test biological sample with a monoclonal antibody to CA-125, wherein said monoclonal antibody has been immobilized on a solid support and said incubation is carried out under conditions permitting the binding of said monoclonal antibody to said CA-125;   b) at the end of the incubation of step a), separating said solid support with immobilized monoclonal antibody and bound CA-125 from said test biological sample;   c) incubating said solid support with immobilized monoclonal antibody and bound CA-125 obtained in step b) with a second antibody that binds to CA-125;   d) at the end of the incubation of step c), determining the amount of second antibody bound to the solid support; and wherein, the total amount of free and complexed antibody is compared with CA-125 levels in one or more control samples and the presence of ovarian cancer is indicated by the total amount of CA-125 in said test sample being higher than in said one or more control samples.   
     
     
         25 . The method of  claim 24 , wherein, in step c, said second antibody is unlabeled and:
 i) at the end of the incubation of step c) the solid support with bound second antibody is separated from unbound second antibody;   ii) incubating the solid support that has been separated from unbound second antibody with a third antibody that is detectably labeled and that binds to said second antibody;   iii) separating the solid support with bound detectably labeled antibody from unbound detectably labeled antibody; and   iv) quantitating the amount of detectable label bound to said solid support.   
     
     
         26 - 28 . (canceled) 
     
     
         29 . A kit comprising a solid support comprising an immobilized monoclonal antibody that binds to CA-125 and one or components selected from the group consisting of: labeled or unlabeled unbound antibody against CA-125; labeled or unlabeled antibody recognizing human antibody; and one or more control samples. 
     
     
         30 . The solid support of  claim 29 , wherein said solid support is a plate or slide made of glass, plastic or metal.